KR20190011100A - Motherplate for producing electroforming mask - Google Patents

Abstract

The present invention relates to a mother plate for producing an electroformed mask. A mother plate (20) according to the present invention is a mother plate (20) used for manufacturing a mask through electroforming, comprising a conductive base material (21). The surface profile (Ra) of the surface of the conductive base material (21), on which a plating layer (15) is produced, is between 30nm and 300nm.

Description

{MOTHERPLATE FOR PRODUCING ELECTROFORMING MASK}

The present invention relates to a base plate for manufacturing electroplate masks. More specifically, the present invention relates to a base plate for manufacturing electroplate masks, in which the plating film formed during the electroforming process is not peeled off and the plating film can be easily separated after the plating film is formed.

Recently, electroforming methods have been studied in the manufacture of thin plates. In the electroplating method, an anode body and a cathode body are immersed in an electrolytic solution, and a power source is applied to electrodeposit a metal thin plate on the surface of the cathode body, so that an ultra thin plate can be manufactured and mass production can be expected.

On the other hand, FMM (Fine Metal Mask) method for depositing an organic material at a desired position by bringing a thin film metal mask (Shadow Mask) into close contact with a substrate is mainly used as a technique of forming a pixel in an OLED manufacturing process.

In the conventional mask manufacturing method using plating, a substrate is prepared and a PR having a predetermined pattern is coated on the substrate. Subsequently, plating is performed on the substrate to form a metal thin plate. Subsequently, the PR is removed, and a mask (or a thin metal plate) having a pattern formed thereon is separated from the substrate to complete the manufacture.

In the process of forming the metal thin plate, a cathode body, that is, a conductive base plate (substrate) is disposed at a predetermined interval in the anode body immersed in the plating liquid, and an electric field is applied between the anode body and the anode body To perform electroplating. When the surface of the negative electrode body is made of a smooth mirror surface, the plating film may not have sufficient strength to adhere to the surface of the negative electrode body, so that the plating film is peeled off during the electroplating process Peeling). On the other hand, if the surface of the negative electrode has a high roughness, the plated film is adhered to the surface of the negative electrode too strongly, and after the electroplating process is completed, there is a problem that the plated film is torn or damaged in the process of separation for use as a mask.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a method of manufacturing a pre-plated mask, which is capable of easily separating a plated film after a plating film is formed, And the like.

The object of the present invention, electroforming (Electroforming) a bed (Mother Plate) as comprising: a conductive base material, the surface roughness of the conductive base material surface to be plated film is produced (R _a) used in the manufacture of masks is 30nm to 300nm And is achieved by a mold plate.

The height difference (R _z ) between the top height (R _peak ) and the bottom (R _valley ) of the irregularities of the conductive substrate surface may be 0.3 μm to 5 μm.

A plated film can be produced on the conductive substrate surface and separated from the conductive substrate surface under the application of an external force.

The conductive substrate may be a doped monocrystalline silicon material.

Doping can be performed at least 10 ¹⁹ cm ^-3 or more.

An insulating portion having a pattern on the conductive substrate may be formed.

The side surface of the insulating portion may have a tapered shape or a reverse tapered shape.

The base plate can be used as a cathode body in electroplating.

According to the present invention configured as described above, the plating film formed during the process is not peeled off, and the plating film can be easily separated after the completion of the plating film production.

1 is a schematic view showing an OLED pixel deposition apparatus using FMM according to an embodiment of the present invention.
2 is a schematic view showing a electroplate plating apparatus according to an embodiment of the present invention.
3 is a schematic view illustrating a mask according to an embodiment of the present invention.
4 is a schematic view showing a process of manufacturing a mask according to an embodiment of the present invention.
5 is a schematic view showing a process of manufacturing a mask according to another embodiment of the present invention.

The following detailed description of the invention refers to the accompanying drawings, which illustrate, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It should be understood that the various embodiments of the present invention are different, but need not be mutually exclusive. For example, certain features, structures, and characteristics described herein may be implemented in other embodiments without departing from the spirit and scope of the invention in connection with an embodiment. It is also to be understood that the position or arrangement of the individual components within each disclosed embodiment may be varied without departing from the spirit and scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is to be limited only by the appended claims, along with the full scope of equivalents to which such claims are entitled, if properly explained. In the drawings, like reference numerals refer to the same or similar functions throughout the several views, and length and area, thickness, and the like may be exaggerated for convenience.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, so that those skilled in the art can easily carry out the present invention.

1 is a schematic view showing an OLED pixel deposition apparatus 200 using an FMM 100 according to an embodiment of the present invention.

1, an OLED pixel deposition apparatus 200 generally includes a magnet plate 300 in which a magnet 310 is accommodated and a cooling water line 350 is disposed, And a deposition source supply part 500 for supplying a deposition source 600.

A target substrate 900 such as a glass on which the organic material source 600 is deposited may be interposed between the magnet plate 300 and the source evaporator 500. The FMM 100 for causing the organic material source 600 to be deposited on a pixel-by-pixel basis may be closely adhered to the target substrate 900 or may be disposed in close proximity. The magnet 310 generates a magnetic field and the FMM 100 can be brought into close contact with the target substrate 900 by a magnetic field.

A stick-type mask (see FIG. 3A) and a plate-type mask (see FIG. 3B) are aligned before being brought into close contact with the target substrate 900, Is required. One mask or a plurality of masks may be coupled to the frame 800. The frame 800 is fixedly installed in the OLED pixel deposition apparatus 200, and the mask can be coupled to the frame 800 via a separate attachment, welding process.

The deposition source supply unit 500 reciprocates in the right and left path and can supply the organic material source 600. The organic material sources 600 supplied from the deposition source supply unit 500 pass the pattern PP formed on the FMM mask 100 And may be deposited on one side of the target substrate 900. The deposited organic material source 600 that has passed through the pattern of the FMM mask 100 may act as the pixel 700 of the OLED.

The pattern PP of the FMM mask 100 may be formed obliquely S (or formed into a tapered shape S) in order to prevent non-uniform deposition of the pixel 700 by a shadow effect . The organic material sources 600 passing through the pattern PP in the diagonal direction along the inclined surface can also contribute to the formation of the pixel 700, so that the pixel 700 can be uniformly deposited in thickness as a whole.

FIG. 2 is a schematic view showing the electroplate plating apparatus 10 according to an embodiment of the present invention. Although FIG. 2 shows the planar electroplating apparatus 10, the present invention is not limited to the form shown in FIG. 2, and it can be applied to all known electroplating apparatuses such as a planar electroplating apparatus and a continuous electroplating apparatus Leave.

2, the electrophotographic plating apparatus 10 according to an embodiment of the present invention includes a plating vessel 11, a cathode body 20, an anode body 30, a power supply unit 40 ). A means for separating the plating film 100 (or the thin metal plate 100) to be used as the mask 100 from the cathode body 20, means for cutting the electrode body 20, And the like (not shown).

A plating liquid (12) is contained in the plating tank (11). The plating liquid 12 may be a material of the plating film 100 to be used as the mask 100 as an electrolytic solution. In one embodiment, when a thin plate of Invar, which is an iron nickel alloy, is manufactured as a plated film 100, a mixed solution of a solution containing Ni ions and a solution containing Fe ions may be used as the plating solution 12. In another embodiment, when a super Invar thin plate, which is an iron nickel cobalt alloy, is made of the plated film 100, for example, a solution containing Ni ions, a solution containing Fe ions, and a solution containing Co ions May be used as the plating liquid (12). Inverted foil and Super Invarned foil are used as FMM (Fine Metal Mask) and Shadow Mask in the manufacture of OLED, and can play an important role in accurately guiding the electron beam to the phosphor. Then, the Invar sheet is from about from about 1.0 X the thermal expansion coefficient of 10 ^-6 / ℃, Super Invar sheet has a coefficient of thermal expansion of about 1.0 X 10 ^-7 / ℃ So that the pattern shape of the mask is not likely to be deformed due to heat energy, and thus it is mainly used in high-resolution OLED manufacturing. In addition to this, the plating solution 12 for the desired plating film 100 can be used without limitation. In this specification, it is assumed that the manufacturing of the thin insulating film 100 (or the invar mask 100) is described as a main example.

A plating liquid 12 can be supplied from an external plating liquid supply means (not shown) to the plating tank 11 and a circulating pump (not shown), a plating liquid 12 (not shown) for circulating the plating liquid 12 in the plating tank 11, And a filter (not shown) for removing impurities of the semiconductor device.

The negative electrode body 20 has a flat plate shape and the like on one side, and the whole of the negative electrode body 20 can be immersed in the plating liquid 12. Although the anode 20 and the anode 30 are vertically arranged in FIG. 2, they may be arranged horizontally. In this case, at least a part or all of the anode 20 in the plating solution 12 Can be immersed.

A plating film 100 may be deposited on the surface of the cathode body 20 and a pattern corresponding to the insulating portion 25 of the cathode body 20 may be formed on the plating film 100. [ The negative electrode body 20 of the present invention can be formed up to a pattern in the process of forming the plating film 100. Therefore, the negative electrode body 20 is referred to as a " mother plate " do. The specific configuration of the surface of the base plate 20 (or the cathode body 20) will be described later.

The anode body 30 is provided at a predetermined interval so as to face the anode body 20 and has a flat plate shape or the like which is flat on one side corresponding to the anode body 20, It can be immersed. The anode body 30 may be made of an insoluble material such as titanium (Ti), iridium (Ir), ruthenium (Ru), or the like. The anode body 20 and the anode body 30 may be spaced apart by several centimeters.

The power supply unit 40 can supply a current necessary for electroplating to the anode body 20 and the anode body 30. The (-) terminal of the power supply unit 40 may be connected to the anode body 20, and the (+) terminal may be connected to the anode body 30.

3 is a schematic diagram illustrating a mask 100 (100a, 100b) according to an embodiment of the present invention.

3, there is shown a mask 100 (100a, 100b) manufactured using a electroplate plating apparatus 10 comprising a base plate 20 (or cathode 20) of the present invention. The mask 100a shown in FIG. 3 (a) is a stick-type mask, and both sides of the stick can be welded and fixed to the OLED pixel deposition frame 800. The mask 100b shown in FIG. 3 (b) is a plate-type mask, which can be used in a pixel forming process in a large area, and the edge of the plate is welded and fixed to the OLED pixel deposition frame 800 . 3 (c) is an enlarged cross-sectional view along the line A-A 'in (a) and (b) of FIG. 3.

A plurality of display patterns DP may be formed on the body of the mask 100 (100a, 100b). The display pattern DP is a pattern corresponding to one display such as a smart phone. When the display pattern DP is enlarged, a plurality of pixel patterns PP corresponding to R, G, and B can be confirmed. The pixel patterns PP may have a tapered shape or a tapered shape (see Fig. 3 (c)). A large number of pixel patterns PP constitute one display pattern DP and a plurality of display patterns DP may be formed on the mask 100 (100a, 100b). Hereinafter, the display pattern DP and the pixel pattern PP may be used in combination as a mask pattern.

It is preferable that the mask pattern PP has a roughly tapered shape or a reverse tapered shape having a shape gradually becoming narrower or wider toward the lower portion from the upper portion to the lower portion, (See Fig. 2), it is more preferable that the mask pattern PP has a shape gradually widening from the upper part to the lower part. The pattern width may be formed to a size of several to several tens of micrometers, preferably to a size of less than 30 micrometers.

4 is a schematic view showing a process of manufacturing the mask 100 according to an embodiment of the present invention.

Referring to FIG. 4 (a), a conductive base material 21 is prepared so that electroforming can be performed. The mother plate 20 including the conductive substrate 21 can be used as a cathode body in electroplating.

The invention in one aspect, that is, the plating film surface roughness of the one surface that is 15 are electrodeposited (R _a) is characterized in that the 30nm to 300nm of a conductive base material 21. This surface roughness can be realized by forming fine irregularities on the surface of the conductive base material 21. The fine irregularities can be formed by a method such as etching, sanding, machining, and polishing.

The fine irregularities can serve to catch the plating film 15 on the surface of the conductive base material 21 during the electroplating process. That is, as the plated film 15 penetrates and forms between the minute unevenness, it can be properly attached without being peeled from the conductive substrate 21.

As described further herein, the surface of the conductive base material 21 surface roughness (R _a) that is less than 30nm, the plated film 15 is generated by the electroforming process the anode body (20) or, bed (20) of And can be peeled off. In contrast, the conductive base material 21 surface, the surface roughness (R _a) of the surface is greater than 300nm, there plating film 15 is so strongly attached to the surface of the anode body 20, even after completion of the electroforming process, the negative electrode member It may be difficult to separate the plated film 15 from the plated film 20. In this case, if the plating film 15 is torn, damaged or wrinkled while the force is applied to force the plating film 15 to be separated, the plating film 15 may become unusable as a product. Thus, the bed 20 of the present invention may be a surface roughness (R _a) of the conductive substrate (21) 30nm to 300nm.

The height difference (R _z ) between the uppermost top height (R _peak ) and the lowermost bottom (R _valley ) of fine irregularities is preferably 0.3 μm to 5 μm. Rz is approximately 10 to 17 times the surface roughness R _a . If the height difference of the unevenness is 0.3 탆 to 5 탆, the electrodeposited plating film 15 is suitably applied to the surface of the anode body 20 And after the electroplating process is completed, the plating film 15 can be separated from the cathode body 20 with a small external force applied thereto. Thus, the plating film 15 may not be damaged at all.

On the other hand, as a conductive material, in the case of metal, metal oxides may be generated on the surface, impurities may be introduced in the course of metal production, and in the case of a polycrystalline silicon substrate, an inclusion or grain boundary may exist. In the case of a conductive polymer base material, there is a high possibility that impurities are contained, and strength. Acid resistance may be weak. An element that interferes with the uniform formation of an electric field on the surface of the base plate 20, such as metal oxide, impurities, inclusions, grain boundaries, and the like, is referred to as "Defect ". Due to the defect, a uniform electric field is not applied to the negative electrode of the above-mentioned material, so that a part of the plating film 15 can be formed non-uniformly. Further, in the case of a polycrystalline substrate material, the position of the pattern formed on the mask may be changed due to the nonuniform characteristics between crystal grains by a heat treatment process for reducing the thermal expansion coefficient of the electroplated film, have.

Unevenness of the plated film 15 and the plated film pattern PP in implementing ultra high image quality of the UHD class or higher may adversely affect pixel formation. Since the pattern width of the FMM and the shadow mask can be formed to a size of several to several ten micrometers, preferably about 5 to 10 micrometers (resolution of 2,000 PPI or more), even a defect of a few micrometers in size has a large specific gravity Of the total.

Further, in order to remove defects in the cathode body made of the above-mentioned material, an additional process for removing metal oxide, impurities and the like may be performed. In this process, another defect such as etching of the cathode body material may be caused have.

Therefore, the present invention can use the base material 21 made of a single crystal silicon. The substrate 21 may be doped with a high concentration of 10 ¹⁹ / cm ³ or more so as to have conductivity. The doping may be performed on the entire surface of the substrate 21 or may be performed only on the surface portion of the substrate 21. [

In the case of doped monocrystal silicon, since there is no defect, the plating film 15 (or the mask 15) having a uniform surface state can be generated without surface defects due to the formation of a uniform electric field on the entire surface during electroplating There is an advantage. The uniform mask 15 can further improve the picture quality level of the OLED pixels. Further, since there is no need to carry out an additional process for removing and eliminating defects, there is an advantage that the process cost is reduced and the productivity is improved.

In addition, in the case of single crystal silicon, there is an advantage that it is easy to realize the above-described surface roughness (R _a ) by utilizing a texturing technique developed in a semiconductor process.

In addition, when the base material 21 made of a silicon material is used, there is an advantage that the insulating portion 25 can be formed only by oxidizing and nitriding the surface of the base material 21 as needed. The insulating part 25 serves to prevent electrodeposition of the plating film 20 and can form the pattern PP of the plating film 15. [

Next, referring to FIG. 4 (b), an insulating portion 25 may be formed on at least one surface of the substrate 21. The insulating portion 25 may be formed with a pattern and may have a pattern by an engraved pattern 26 of a tapered or inverted tapered shape. The insulating portion 25 is a portion formed (protruded) on one surface of the substrate 41 (with an embossed shape) and may have an insulating property to prevent the formation of the plated film 15. Accordingly, the insulating portion 25 may be formed of any one of photoresist, silicon oxide, and silicon nitride. The insulating portion 25 can form silicon oxide and silicon nitride on the base material 21 by a method such as vapor deposition and perform thermal oxidation or thermal nitridation using the base material 21 as a base It can also be used. A photoresist may be formed using a printing method or the like. When a pattern is formed using a photoresist, a multiple exposure method, a method of varying exposure intensity for each region, or the like can be used. The insulating portion 25 may have a thickness of about 5 占 퐉 to 20 占 퐉 so as to be thicker than the plating film 15 to be described later. Thus, the base plate 20 can be manufactured.

Next, referring to FIG. 4C, an anode body (not shown) facing the base plate 20 (or the anode body 20) is prepared. An anode body (not shown) is immersed in a plating liquid (not shown), and all or a part of the base plate 20 may be immersed in a plating liquid (not shown). The plating film 15 may be formed by electrodeposition on the surface of the base plate 20 due to the electric field formed between the base plate 20 (or the anode body 20) and the anode body facing the anode plate. However, since the plating film 15 is formed only on the exposed surface of the substrate 21 and no plating film 15 is formed on the surface of the insulating portion 25, the pattern PP is formed on the plating film 15 .

It is preferable to form the plating film 15 only until the upper end of the insulating portion 25 is turned over since the plating film 15 is thickened from the surface of the substrate 21 by electrodeposition. That is, the thickness of the plating film 15 may be smaller than the thickness of the insulating portion 25. [ Since the plated film 15 is filled in the pattern space of the insulating part 25 and is electrodeposited, the plating film 15 can be formed having a tapered shape having a reverse phase to the pattern of the insulating part 25.

The plating film 15 is deposited and attached on the surface of the base plate 20 having _a surface roughness Ra of 30 to 300 nm so that the plating film 15 is formed after the plating film 15 is formed until the electroplating process is completed ), Deformation such as peeling, wrinkling, tearing and the like do not occur. Thus, the alignment can be clearly maintained without changing the position of the mask pattern PP of the plated film 15. [

Next, the step of removing the insulating portion 25 is selectively performed, and the base plate 20 (or the anode body 20) is lifted out of the plating liquid (not shown). When the plating film 15 and the base plate 20 are separated from the plating liquid, the portion where the plating film 15 is formed constitutes the mask 100 (or the mask body), and the plating film 15 is not formed A pixel pattern PP, a display pattern DP (or a mask pattern) can be formed. In the process of separating the plating film 15 and the base plate 20, since the plating film 15 is separated by only a weak external force, the plating film 15 is not damaged at all.

In another embodiment, referring to Figure 5 (a), a conductive substrate 21 is prepared. 4 (a), and the description thereof will be omitted.

Next, referring to FIG. 5 (b), electroconductive plating is performed using the conductive base material 21 itself as a base plate 20. FIG. A plating film 15 may be formed on the entire surface of the conductive substrate 21. [ No deformation such as peeling, wrinkling or tearing of the plating film 15 occurs after the plating film 15 is formed until the electroplating process is completed. The electroplating process is the same as in (c) of FIG. 4, so that detailed description is omitted.

Next, referring to FIG. 5C, the plating film 15 is separated from the base plate 20 (or the cathode body 20). The plating film 15 is not formed with a separate mask pattern. In this separation process, since the plating film 15 is separated by only a weak external force, the plating film 15 is not damaged at all.

Next, referring to FIG. 5 (d), a mask pattern PP can be formed on the plating film 15. The mask pattern PP may be formed by a lithography process using a photoresist, an etching process, a laser etching process, or the like. The mask pattern PP may have a rectangular shape, a taper shape, an inverted taper shape, or the like.

On the other hand, after the plating film 15 is formed on the base plate 20 in the step of FIG. 4 (c) or FIG. 5 (b), the plating film 15 may be subjected to heat treatment. The heat treatment may be performed at a temperature of 300 ° C to 800 ° C. In general, the invar sheet produced by electroplating is higher in thermal expansion coefficient than the invar sheet produced by rolling. Thus, the thermal expansion coefficient can be lowered to about 2.0 × 10 ^-6 / ° C. by performing the heat treatment on the thinned plate, which may cause slight deformation of the thinned plate during the heat treatment. Thus, well attached to the surface roughness (R _a) is 30nm to 300n of the cathode member (20) or the substrate (21) good and before the coating layer 15 on the plating film 15. The anode body 20 The shape of the plated film 15 is kept constant, and the fine deformation due to the heat treatment can be prevented, and the thermal expansion coefficient can be lowered.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken in conjunction with the present invention. Variations and changes are possible. Such variations and modifications are to be considered as falling within the scope of the invention and the appended claims.

10: Electroplating device
11: Plating tank
12: plating solution
15: plated film
20: plate, negative electrode
21: Conductive substrate
25:
26: Insulation part Cathode pattern
30: anode
40: Power supply
100: mask, shadow mask, FMM (Fine Metal Mask)
200: OLED pixel deposition apparatus
DP: Display pattern
PP: pixel pattern, mask pattern

Claims (8)

As a mother plate used for manufacturing a mask by electroforming,
And a surface roughness (R _a ) of the conductive base surface on which the plated film is formed is 30 nm to 300 nm. The method according to claim 1,
_Wherein the height difference (R _z ) between the top height (R _peak ) and the bottom (R _valley ) of the irregularities of the conductive substrate surface is 0.3 μm to 5 μm. The method according to claim 1,
Wherein a plated film is formed on the conductive substrate surface and separated from the conductive substrate surface under the application of an external force. The method according to claim 1,
Wherein the conductive substrate is a doped monocrystalline silicon material. 5. The method of claim 4,
The doping is performed at least 10 ¹⁹ cm ^-3 or higher, the matrix. The method according to claim 1,
A base plate on which an insulating portion having a pattern is formed on a conductive substrate. The method according to claim 6,
And the side surface of the insulating portion has a tapered shape or a reverse tapered shape. The method according to claim 1,
The base plate is used as a cathod body in electroplating.

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